The present invention relates to a collapsible structural element and, more particularly to a collapsible beam which can be folded into a compact form.
Collapsible structural elements are well known in the art. Examples of such collapsible structural elements are disclosed in U.S. Pat. Nos. 395,086; 979,408; 1,053,933 and 1,100,829.
However, none of the inventions described in the above patents disclose a collapsible structural element such as a beam made of a material having a self memory which enables expansion of the structural element so as to adopt to a desired three dimensional conformation upon unfolding of the structural element from a packed configuration into an open configuration.
There is thus a widely recognized need for, and it would be highly advantageous to have, a collapsible structural element such as a beam which can be expanded so as to adopt to a desired three dimensional conformation upon unfolding of the beam from a packed configuration into an open configuration.
It would be further advantageous to have such a collapsible beam element which can be used to support a larger structural element such as, e.g., a stretcher, bridge or a ladder and which further enables compact packing of such larger structural element.
It would be further advantageous to have such a collapsible beam which is made of a material having a predefined shape thereby enabling expansion of the collapsible beam so as to feature any desired three dimensional conformation.
Another prior art device that attempts to remedy the deficiencies of the above patents is Isaac, U.S. Pat. No. 3,300,910. Isaac teaches a reelable member having inflation means that allows the member to expand after been unreeled. Inflatable elements located within its hollow interior permit the member to retain its shape while unreeled. When reeled-in, the member is collapsible into a compact form.
According to the present invention there is provided a collapsible structural element, including: (a) a flexible structural member having a predetermined three dimensional conformation; and (b) a hollow defined by the three dimensional configuration of the flexible structural member, wherein the flexible structural member may be collapsed so as to substantially eliminate the hollow, thereby enabling folding of the collapsible structural element from an open configuration into a packed configuration. The flexible structural member readopts the predetermined three dimensional conformation when unfolding the collapsible structural element from a packed configuration into an open configuration.
Specifically, according to the present invention there is provided a collapsible beam element, including: (a) an elongated flexible structural member having a predetermined cross section; and (b) a hollow defined by the cross section of the flexible structural member, wherein the flexible structural member may be collapsed so as to substantially eliminate the hollow, thereby enabling folding of the beam element from an open configuration into a packed configuration, and wherein the flexible structural member readopts the predetermined cross section when unfolding the beam element from a packed configuration into an open configuration.
According to further features in preferred embodiments of the invention described below, the flexible structural member may include a first and second members, the first and second members being interconnected so as to define the hollow.
According to still further features in preferred embodiments of the invention described below, the beam element is used as a stretcher beam. Alternatively, the beam element may be used as a ladder beam or bridge beam, amongst many other possible usages.
The present invention successfully addresses the shortcomings of the presently known configurations by providing a collapsible structural element such as a beam made of a material having a predetermined shape, or forced to a predetermined shape, which enables expansion of the structural element so as to adopt a desired three dimensional conformation upon unfolding of the structural element from a packed configuration into an open configuration.
When using a device according to the present invention, the collapsible beam element is collapsed and rolled so as to adopt a compact packed configuration. The beam element is then unfolded so as to readily adopt a predetermined three dimensional conformation,